RESUMO
OBJECTIVE: To evaluate the reproducibility of three nonverbal facial expressions using a three-dimensional motion capture system. DESIGN: Prospective, cross-sectional, controlled study. SETTING: Glasgow Dental Hospital and School, University of Glasgow, United Kingdom. PATIENTS AND PARTICIPANTS: Thirty-two subjects, 16 males and 16 females. METHODS: With a three-dimensional video passive stereophotogrammetry imaging system, maximal smile, cheek puff, and lip purse were captured for each subject. Anatomical facial landmarks were digitized on the first frame and then tracked automatically. The same facial expressions were captured 15 minutes later. MAIN OUTCOME MEASURES: The magnitude of each expression and speed of landmark displacement were calculated. The landmark motion curves were spatially and temporally aligned to calculate the similarity of the dynamic movements of the same landmarks between the captures. RESULTS: There were no significant differences between individuals for magnitude (P = .892) or for speed (P = .456). There were significant differences in landmark movement similarity (P = .011); similarity was more reproducible for maximal smile. There was no significant gender effect on the difference in magnitude. There was a significant gender effect on speed to reach maximal smile (P = .044) and a pursed-lip expression (P = .038). There was a significant gender effect on landmark movement similarities (P = .031) for cheek puff expression. CONCLUSIONS: There were no differences in magnitude and speed for maximal smile, cheek puff, and lip purse between the two captures for all participants. For individual expressions, maximal smile expression had the highest similarity value for individual landmarks.
Assuntos
Expressão Facial , Imageamento Tridimensional/métodos , Fotogrametria/métodos , Adolescente , Adulto , Pontos de Referência Anatômicos , Estudos Transversais , Feminino , Humanos , Masculino , Estudos Prospectivos , Reprodutibilidade dos Testes , EscóciaRESUMO
This study applies recent advances in 3D virtual imaging for application in the prediction planning of dentofacial deformities. Stereo-photogrammetry has been used to create virtual and physical models, which are creatively combined in planning the surgical correction of anterior open bite. The application of these novel methods is demonstrated through the surgical correction of a case.
Assuntos
Mordida Aberta/cirurgia , Planejamento de Assistência ao Paciente , Interface Usuário-Computador , Cefalometria/métodos , Desenho Assistido por Computador , Tomografia Computadorizada de Feixe Cônico/métodos , Humanos , Imageamento Tridimensional/métodos , Masculino , Má Oclusão Classe II de Angle/cirurgia , Má Oclusão Classe II de Angle/terapia , Osteotomia Mandibular/métodos , Osteotomia Maxilar/métodos , Modelos Anatômicos , Mordida Aberta/terapia , Procedimentos Cirúrgicos Ortognáticos/métodos , Osteotomia de Le Fort/métodos , Fotogrametria/métodos , Retrognatismo/cirurgia , Retrognatismo/terapia , Técnicas de Movimentação Dentária/métodos , Resultado do Tratamento , Adulto JovemRESUMO
PURPOSE: The aim of this study was to evaluate the impact of orthognathic surgical correction of facial asymmetry and maxillary hypoplasia on the magnitude and pattern of facial expressions. PATIENTS AND METHODS: This study was carried out on 2 cohorts of patients: in group 1, 10 patients had surgical correction of facial asymmetry; in group 2, 13 patients had Le Fort I osteotomy to correct maxillary hypoplasia. The patients were asked to perform 3 facial expressions (maximal smile, lip purse, and cheek puff) that were recorded using the Di4D image-capture system before and after surgery. The capture of each expression generated 180 3-dimensional (3D) facial images. Twenty-seven facial soft tissue landmarks were digitized on the first frame of the 3D image of each expression and a mathematical generic mesh was applied on the 3D model to clone each patient's face. The cloned mesh was superimposed automatically on each sequence of the 3D images to evaluate the pattern of facial expressions. The digitization of facial landmarks was satisfactorily accurate and reproducible. RESULTS: In group 1, the asymmetry of facial expressions was significantly decreased after surgical correction (P = .0458). In group 2, Le Fort I osteotomy decreased the magnitude of facial expressions (P = .0267). CONCLUSION: This study confirmed that orthognathic surgery affects the dynamics of facial expressions; this should be considered when planning the surgery and informing patients about the surgical correction of dentofacial deformities.
